Please i want to modify this formula to change when column content below it
change. "=TODAY()" or if other way to do it.

A B C
A1 Last Update 02/06/2009 03/07/2008
B2- 30% C2-40%
B3- 80% C3- 20%
B4- 45% C4- 90%

Assuming i change 40% on C2 Change to 100% today then 03/07/2008 should
automatically change to 06/24/2009. Please can anybody help me with this?
Appreciate your precious time. Thanks